CONSERVATION

Protecting Our Future

We work to ensure that lands we acquire or those placed under a conservation easement are properly conserved and stewarded, ensuring their conservation benefits last long into the future.

Here are just a few of the species we help protect.

Western Joshua Tree

As of 2023, the Western Joshua tree is a candidate species with the State of California. This provides it with the same protection as an endangered species at this time. Due to warming temperatures, invasive plant species, drought, and severe fires, this species is projected to face extreme difficulties within its range.
Our Puma Canyon Ecological Reserve contains some of the most dense Joshua tree woodland near the transverse ranges. Our Portal Ridge Wildlife Preserve also contains hundreds of acres of threatened Joshua tree woodland in the Antelope Valley, the western-most portion of the Mojave Desert. We prioritize and acquire lands with Joshua tree woodland, employ adaptive management techniques to our lands to ensure their resiliency, and work with and advise the California Department of Fish and Wildlife (CDFW) on issues pertaining to the conservation of this species.
The Wildlife Conservation Board awarded us $230,000 to acquire over 300 acres of land to create Puma Canyon Ecological Reserve, a strong-hold for the Western Joshua tree.
In 2024, we were selected by the National Fish and Wildlife Foundation (NFWF) under the Western Joshua Tree Conservation Fund (WJT Fund) to provide assistance to the California Department of Fish and Wildlife (CDFW) in its efforts to address threats to the western Joshua tree and its habitats by working closely with CDFW in identifying and bring to CDFW for its consideration western Joshua tree conservation opportunities.
CDFW has selected our organization to serve as a consultant to assist them in acquiring conservation lands and pursuing other land protection opportunities, as well as identifying and managing enhancement and restoration opportunities, on the northside of the Transverse Range within the Antelope Valley of San Bernardino and Los Angeles counties.
We have received smaller grants from various partners in order to conduct restoration activities in post-fire Joshua tree woodland, and study new restoration techniques.
We work closely with CDFW on the conservation of this species. Our also work closely with Los Angeles County, California State Parks, and other NGO non-profit organizations.
Our organization is at the forefront of a relatively new field of study; the restoration of Western Joshua tree habitat. We work closely with our partners to develop methodology to care for and restore Joshua tree woodland. Some of our latest techniques included in and around our 2081(a) state permits include:
- Removing invasive plants from Joshua tree understory.
- Conducting pile burns of invasive vegetation.
- Targeted sheep grazing within the woodlands.
- Joshua tree post-fire surveys.
- Collecting seeds, storing them, and growing them in our greenhouse.
- Out planting Joshua tree seedlings in post-fire areas, we well as establishing populations in previous woodland cleared for agriculture.
We share this information with other organizations to benefit the species across its range.

Desert Tortoise

The desert tortoise is a federally threatened and state endangered species, placed under the Endangered Species Lists in 1989 and 1990. A highly virulent respiratory disease, along with other human-induced challenges reduced the population sharply in the 1980’s.
Tortoise conservation is a top priority at THC. We have an entire project area consisting of over 4,000 acres to help contribute to their protection. We work closely with the Bureau of Land Management to protect an additional 250,000 acres in the West Mojave by restoring illegal routes and trails that cut through their habitat. We also hold education and outreach events for the public and teach people how they can protect these iconic Mojave Desert denizens.
In 2023, the Wildlife Conservation Board awarded THC $1.9 million in grant funding to pursue active conservation of the desert tortoise with our partner, Hardshell Labs. Their ingenuity and technology will be implemented during this grant work in order to prevent the predation of baby tortoises by ravens, as well as identify and fortify the dense population islands that still persist in the Western Mojave Desert.
Our generous grants from Edison International, and the Desert Tortoise Council have enabled us to collect the necessary data to pursue the recently awarded WCB grant.
We work closely with Hardshell Labs and tortoise biologist and expert Tim Shields.
We also work closely with the Bureau of Land Management (BLM), as well as US Fish and Wildlife Service and the California Department of Fish and Wildlife. We work with other NGO’s and conservation groups, and with all of this combined experience pursue land acquisitions, land stewardship, and recovery of the species.
The combined efforts of THC and Hardshell Labs have led to a significant drop both in unauthorized OHV usage and in raven populations near our project area, as well as a large amount of data related to tortoise numbers on our lands. This data is reported to our other government partners so that holistic management decisions can be made. Our current WCB grant will continue to provide additional data in the years to come.
In addition, our restoration and education efforts on illegal OHV routes has given us some of the highest success rates regarding habitat restoration of any organization conducting restoration in the Western Mojave Desert.

Swainson’s Hawk

“The Swainson’s Hawk (Buteo swainsoni) has a long history of breeding in California, but a severe decline in the statewide breeding population was identified in 1979, when in all of southern California only two pairs were found, one in the Antelope Valley of the western Mojave Desert… Though the Antelope Valley population has grown since 1980, its nesting and foraging habitat now face multiple threats. To conserve occupied nesting territories, we recommend the creation of nesting and foraging habitat reserves that include both native desert and cultivated alfalfa close to existing conserved land.” (Bloom et al., 2023).
As the southern-most breeding area of the Swainson’s hawk in California, THC is dedicated to the success and protection of this incredible raptor at Portal Ridge Wildlife Preserve and in the greater Antelope Valley. We work with experts like Bloom Biological Inc. in the field to guide our land acquisition selections, as well as rely on their survey data to ensure that valuable nesting as well as foraging habitat is being conserved and prioritized.
We have received grants to improve the habitat of Swainson’s hawk within the Antelope Valley from the National Audubon Society, the San Fernando Valley Chapter of the Audubon Society, and other partners to help us accomplish land acquisition, management, and fund monitoring equipment.
We partner with other professionals like Bloom Biological Inc., the Audubon, the California Department of Fish and Wildlife, Los Angeles County, and others to ensure that the Swainson’s hawks have land on which to raise their young, and forage for food.
In 1979, Dr. Peter Bloom recorded 1 breeding pair remaining in the Antelope Valley. There were 18 nesting pairs recorded in 2023. We are seeing some success, but much more work is required to assist their recovery. We are working towards outfitting more Swainson’s hawks with transmitters in order to better understand their movements, population, and migration patterns so that we may better conserve land for them in their southern-most breeding area in the Antelope Valley.

Monarch Butterfly

“The iconic black and orange monarch butterfly is known for its astonishing long-distance annual migration and reliance on milkweed as its obligate larval host plant. Though genetically similar, there are two subpopulations of monarchs in North America, with the eastern population overwintering in Mexico and breeding in the midwestern states, and the western population overwintering in coastal California and fanning out across the west from Arizona to Idaho.
Both North American migratory populations have declined over the past twenty years due to a suite of interrelated factors including habitat loss in breeding and overwintering sites, habitat degradation, disease, pesticide exposure, and climate change. Recently the western population has experienced dramatic swings, for a low of less than 2,000 in 2020-21 to over 200,000 in 2021-22 (Xerces Society Western Monarch Count)
In 2014, monarchs were petitioned to be listed under the federal Endangered Species Act. In December 2020, the U.S. Fish and Wildlife Service found that listing was warranted but precluded by other listing actions on its National Priority List. The monarch is currently slated to be listed in 2024.” -Information from CDFW
We are dedicated to the preservation of this pollinator and have installed multiple Monarch Waystations at our Puma Canyon Ecological Reserve (PCER). We host a yearly, public educational event as well as conduct yearly milkweed and monarch surveys on the Reserve. Our board Treasurer also hosts multiple educational and tabling events throughout Southern California to educate people about the monarch and how they can help with the preservation of this species. Both our Puma Canyon Ecological Reserve and Portal Ridge Wildlife Preserve host native milkweed plants, as well as monarch butterflies. Our acquisitions, preservation, and adaptive management of the lands assists the monarchs with their feeding and breeding as they travel to their coastal California overwintering sites.
In 2023, we were awarded a $230,000 grant from the National Fish and Wildlife Foundation (NFWF) to further improve monarch habitat on our Reserve. We have catalogued and mapped milkweed throughout the Reserve for the last 8 years. These data, along with our butterfly surveys, have allowed us to learn and plan new ways to improve their feeding and breeding opportunities here. We will also conduct invasive weed removal so that native milkweed and other nectar plants can have less competition, and less fire risk.
Our initial grant of $230,000 from the Wildlife Conservation Board allowed us to acquire the land within PCER.
The Wildlife Conservation Board of California allowed our initial creation of PCER. Our board Treasurer Gina Charpentier, brought her knowledge, experience, and passion for the monarch butterfly to THC and kick-started an entire program of milkweed and monarch butterfly monitoring and education. Our Puma Committee and hard-working volunteers have collected valuable data on this species in our Reserve. NFWF’s recent award of $230,000 will allow us to continue and bolster these activities.
Since 2017, we have hosted our annual Monarch Waystation event here at PCER as well as other mobile events that have educated thousands of people from around Southern California about the monarch butterfly, what they can do to help, and how they can grow their own butterfly gardens. Our waystations have contributed to thousands of monarch butterflies at our California coastal overwintering sites.
Click here to view our milkweed expansion efforts!

Mountain Lion

While Southern California and Central Coast mountain lions face a multitude of threats, the greatest challenges stem from habitat loss and fragmentation and the consequent impact on their genetic health. Due to extreme isolation caused by roads and development, the Southern California populations exhibit high levels of inbreeding, and, with the exception of the endangered Florida panther, have the lowest genetic diversity observed for the species globally (Ernest et al. 2014; Riley et al. 2014; Gustafson et al. 2018; Benson et al. 2019). The number of mountain lions in the North Coast and inland populations (Western Sierra Nevada, Eastern Sierra Nevada, and the genetic cluster centered in the state of Nevada) is not well established; however, these populations are better connected than Southern California and Central Coast mountain lions, and they show relatively high levels of genetic diversity.
Information courtesy of the Center for Biological Diversity.
Our Portal Ridge Wildlife Preserve (PRWP) is comprised of over 5,700 acres of elevational gradients spanning from the Angeles National Forest, to the Mojave Desert foothills of the transverse ranges (San Gabriel Mountains), to the Antelope Valley floor. These lands provide the lions with plentiful food and water sources from perennial springs, as well as connectivity and corridors through this local region. The creation of a statewide corridor is imperative to the genetic health of this species, connecting lions from the Sierras, to the Tehachapi’s, the Transverse Ranges, the San Bernardino Mountain, Santa Ana’s and ultimately the Santa Rosa Mountains in San Diego County.
Our PRWP is one of the important pieces of this puzzle.
Our $15,000 grant from Conservation Lands Foundation has allowed us to fund an internship with Chaffey College (Rancho Cucamonga, CA). to assist us in our lion data collection on PRWP.
Some of our partners in this work include: the California Department of Fish and Wildlife (CDFW), Conservation Lands Foundation, as well as our board director Dan Potter, and camera trapper and photographer, Johanna Turner.
In addition to preserving land for mountain lions, THC is photographing and data basing lion movement throughout Portal Ridge Wildlife Preserve. This data will contribute to the population data on this species for their conservation in Southern California. With the help of CDFW, we will also begin our scat collection program. This passive DNA collection technique will allow us to study the lions so that we can better understand how to care for the land and its residents.

A native California bee is rolling around in the pollen of a short-joint beavertail cactus. The flower is richly magenta, and the bee is bathed in yellow pollen.

Native Bees

Many of our native bee pollinators are at risk, and the status of many more is unknown. Of the roughly 3,600 species of bees in North America, more than 90 percent lead solitary rather than social lives. Habitat loss, alteration, and fragmentation, pesticide use, climate change and introduced diseases all contribute to declines of bees. We do not know the status of most bees because there are so many species. Unfortunately, all indications suggest bees are in decline based on assessments of specific groups of bees. A recent analysis by the Xerces Society and the International Union for Conservation of Nature (IUCN) found that 28% of bumble bees in Canada, the United States, and Mexico are in an IUCN Threatened Category. According to NatureServe, 50% of leafcutter bee species and 27% of mason bee species are “at risk”.
For more information and helpful tips visit the Xerces Society.
Our Portal Ridge Wildlife Preserve, together with Puma Canyon Ecological Reserve hosts dozens of species of pollinators. Due to the solitary nature of many bees, we do not know exactly how many more species might inhabit these lands. Our land management practices such as removing invasive plants, creating bare ground spaces, and encouraging native forb and wildflower growth, all contribute to potential bee nesting and foraging habitat.
More information coming soon!
THC has partnered with Antelope Valley College to study what species of bees are present in Portal Ridge Wildlife Preserve as well as track population data over time.
In order to understand how the bee population looks and is responding to climate change and land management practices, we are partnering with Antelope Valley Community College in Lancaster, California. As part of their NSF Bee grant studies, they will be surveying and monitoring PRWP as well as cataloguing and identifying species.
Check out our survey data from 2024.

Western Burrowing Owl

The Western burrowing owl (Athene cunicularia hypugaea) is currently listed as a Candidate Species [by the State of California] and was unanimously voted so by the California Fish and Game Commission on October 10th, 2024. The species is now receiving the same protections as an endangered species as the Department of Fish and Wildlife conducts its review. Non-game scientists have long been concerned about their viability and survival. Breeding populations have especially declined in the central and southern coastal areas, due in large part to a combination of habitat loss and eradication of the ground squirrels that dig out the burrows where the owls make their nests. Information courtesy of CDFW.
"Statewide surveys by the Institute for Bird Populations showed a 60% decline in California’s burrowing owl colonies from the 1980s to the early 1990s, and a further 11% decline in breeding pairs by 2007. Loss of breeding colonies has accelerated since 2015. Burrowing owls have been eliminated as a breeding species from at least 19 of the 51 California counties where they formerly occurred and are close to being wiped out in 10 other counties." - Center for Biological Diversity
The CBD and other petitioners have recently sought State protections for the owl, and a review of their status is currently underway.
We work closely with experts at Bloom Biological Inc., California Department of Fish and Wildlife and California State Parks in order to safeguard the owls in our region of the Antelope Valley. We have identified areas of high priority for owl habitat, and are working to improve that habitat as well as protect the lands they are living on through acquisition efforts.
THC is working with our partners in order to maintain artificial burrows on State Parks lands as well as install artificial burrows on our own lands.
We work closely with CDFW on the conservation of this species. Our also work closely with Bloom Biological Inc. and California State Parks.
We are currently working with Bloom Biological Inc. to maintain the artificial burrows and improve the habitat on State Parks lands, due to the important population of owls that is hosted there. We are working to survey and identify areas that the young fledge to so that we can acquire, protect, and improve these lands.
We are surveying and photographing the owls throughout the year to count nests and young produced, as well as surveying for ground squirrel populations. Our goal is to improve the ground squirrel health on our lands in order to create sustainable burrowing owl colonies and locations for the young to fledge to.
We are fighting to save lands for burrowing owls, especially in the face of the illegal mulch dumping that is occurring in the Antelope Valley. This accelerated issue has the potential to monopolize available lands and reduce the burrow availability for the owls.